Field of the Invention
Embodiments of the invention relate to a touch sensor integrated type display device and more particularly a touch sensor integrated type display device capable of improving performance of touch precision at a corner part or edge areas thereof.
Discussion of the Related Art
In recent years, various input devices such as a keyboard, a mouse, a joystick and a digitizer have been used to interface between a user and home appliances or telecommunication devices. However, when a user makes use of the input devices, the user's dissatisfaction may increase because the user is required to learn how to use the input devices and because the input devices occupy space. Therefore, a convenient and simple input device that can reduce erroneous operation is required. According to the requirement, there is proposed a touch sensor that can input information by direct contact of a screen with a user's finger or a pen while seeing the input devices.
The touch sensor has a simple configuration capable of minimizing erroneous operations. Also, the user can perform an input action without using a separate input device, and can quickly and easily manipulate a device through contents displayed on a screen. Accordingly, the touch sensor has been applied to various display devices.
The touch sensor used in the display devices may be classified into an add-on type touch sensor, an on-cell type touch sensor and an integrated type (which is also called an in-cell type) touch sensor. The add-on type touch sensor is configured such that a display device and a touch sensor are individually and/or separately manufactured, and then the touch sensor is attached to an upper substrate or an upper portion of the display device. The on-cell type touch sensor is configured such that components constituting a touch sensor are directly formed on the surface of an upper portion of the display device, such as an upper glass substrate. The integrated type touch sensor is configured such that a touch sensor is integrated into a display device to make it a thin shape and enhance durability thereof.
The add-on type touch sensor causes the thickness of a display device to increase because the add-on type touch sensor has a structure in which the add-on type touch sensor is mounted on the display device. Further, visibility of the display device is reduced because of a reduction in a brightness of the display device resulting from the increased thickness.
On the other hand, the on-cell type touch sensor shares the glass substrate with the display device because the on-cell type touch sensor has the structure in which the on-cell type touch sensor is formed on the surface of the glass substrate of the display device. Therefore, a thickness of the display device using the on-cell type touch sensor is less than a thickness of the display device using the add-on type touch sensor. However, the entire thickness of the display device implementing the on-cell type touch sensor increases because of use of a touch driving electrode layer, a touch sensing electrode layer, and an insulating layer for insulating the touch driving electrode layer and the touch sensing electrode layer which constitute the on-cell type touch sensor.
Accordingly, the embodiments of the invention are focused on the integrated type touch sensor in that it is possible to achieve a thin shape of the display device and enhance a durability of the display device, thereby resolving the problems of the add-on type and on-cell type touch sensors.
Hereinafter, a related art a touch sensor integrated type display device will be described with reference to FIG. 1. FIG. 1 is a top plan view illustrating a related art touch sensor integrated type display device.
Referring to FIG. 1, the touch sensor integrated type display device includes an active area AA displaying data and a bezel area BA disposed at outside of the active area AA. The active area includes touch electrodes formed therein, and the bezel area BA includes wires and a gate driving circuit formed therein.
More specifically, the active area AA includes a plurality of first touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34 and Tx41 to Tx44, a plurality of first sub-routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, and TW41 to TW44, and a plurality of second touch electrodes Rx1 to Rx3. The plurality of first touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34 and Tx41 to Tx44 are divided in a first direction (e.g., x-axis direction) and second direction (e.g., y-axis direction) which are cross to each other. The plurality of first sub-routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, and TW41 to TW44 are connected to the plurality of first touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34 and Tx41 to Tx44, respectively and arranged in the second direction. Each of the plurality of second touch electrodes Rx1 to Rx3 is disposed between first touch electrodes Tx11 to tx41 and Tx12 to Tx42, Tx12 to Tx42 and Tx13 to Tx43, Tx13 to Tx43 and Tx14 to Tx44 neighbored in the first direction.
The plurality of first touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34 and Tx41 to Tx44 are connected to the first connection wires TW1c to TW4c, and a plurality of first main-routing wires TW1 to TW4 through the first sub-routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, thereby forming a plurality of first touch electrode serials Tx1 to Tx4 arranged in the first direction in the active area AA.
More specifically, 1-1 touch electrodes Tx11 to Tx14 arranged in a first row are connected to each other by the 1-1 sub-routing wires TW11 to TW14 which are connected to the 1-1 touch electrodes Tx11 to Tx14, respectively, a 1-1 connection wire TW1c which connects the 1-1 sub-routing wires TW11 to TW14, and a 1-1 main-routing wire TW1 connected to the 1-1 connection wire TW1c, thereby forming a 1-1 touch electrode serial Tx1.
1-2 touch electrodes Tx21 to Tx24 arranged in a second row are connected to each other by the 1-2 sub-routing wires TW21 to TW24 which are connected to the 1-2 touch electrodes Tx21 to Tx24, respectively, a 1-2 connection wire TW2c which connects 1-2 sub-routing wires TW21 to TW24, and a 1-2 main-routing wire TW2 connected to the 1-2 connection wire TW2c, thereby forming a 1-2 touch electrode serial Tx2.
1-3 touch electrodes Tx31 to Tx34 arranged in a third row are connected to each other by the 1-3 sub-routing wires TW31 to TW34 which are connected to the 1-3 touch electrodes Tx31 to Tx34, respectively, a 1-3 connection wire TW3c which connects 1-3 sub-routing wires TW31 to TW34, and a 1-3 main-routing wire TW3 connected to the 1-3 connection wire TW3c, thereby forming a 1-3 touch electrode serial Tx3.
1-4 touch electrodes Tx41 to Tx44 arranged in a fourth row are connected to each other by the 1-4 sub-routing wires TW41 to TW44 which are connected to the 1-4 touch electrodes Tx41 to Tx44, respectively, a 1-4 connection wire TW4c which connects 1-4 sub-routing wires TW41 to TW44, and a 1-4 main-routing wire TW4 connected to the 1-4 connection wire TW4c, thereby forming a 1-4 touch electrode serial Tx4.
A 2-1 touch electrode Rx1 of the plurality of second electrodes Rx1 to Rx3 is disposed between 1-5 touch electrodes Tx11 to Tx41 arranged in a first column and 1-6 touch electrodes Tx12 to Tx42 arranged in a second column, thereby forming a 2-1 touch electrode serial Rx1.
A 2-2 touch electrode Rx2 of the plurality of second electrodes Rx1 to Rx3 is disposed between 1-6 touch electrodes Tx12 to Tx42 arranged in a second column and 1-7 touch electrodes Tx13 to Tx43 arranged in a third column, thereby forming a 2-3 touch electrode serial Rx3.
A 2-3 touch electrode Rx3 of the plurality of second electrodes Rx1 to Rx3 is disposed between 1-7 touch electrodes Tx13 to Tx43 arranged in a third column and 1-8 touch electrodes Tx14 to Tx44 arranged in a fourth column, thereby forming a 2-4 touch electrode serial Rx4.
The bezel area BA is disposed at outside of the active area AA, and includes a gate driving circuit GD and wires. The gate driving circuit GD is formed in a gate in panel (GIP) type in the bezel area BA to drive gate lines of the display device. The wires include the touch wires TW11 to TW14, TW21 to TW24, TW31 to TW34, TW41 to TW44, TW1c to TW4c, TW1 to TW4 and RW1 to RW3 connected to the first and second touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, Tx41 to Tx44 and Rx1 to Rx3, gate lines connected to the gate driving circuit GD, and data lines connected to a data driving circuit.
The first and second touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, Tx41 to Tx44, and Rx1 to Rx3 are formed by dividing a common electrode of the display device. Accordingly, the first and second touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, Tx41 to Tx44, and Rx1 to Rx3 are operated as the common electrode in a display mode and operated as touch electrodes for perceiving touch positions in a touch mode.
If fingers or conductive material such as a stylus pen approaches or touches (hereinafter, referred to as “touch”) to the active area AA of the related touch sensor integrated type display device, it perceives a change of capacitance between the first and second touch electrodes near to a touch position and finds the touch position.
Hereinafter, a touch precision for perceiving touch positions according to touch positions will be described with reference to FIG. 2. FIG. 2 is a top plan view illustrating touch positions of the related art touch sensor integrated type display device to explain a difference of touch accuracy according to the touch positions.
The related art touch sensor integrated type display device shown in FIG. 1 includes the first and second touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, Tx41 to Tx44, and Rx1 to Rx3 formed by dividing a common electrode in the active area AA. The magnitude of mutual capacitance between the first and second touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, Tx41 to Tx44, and Rx1 to Rx3 is different according to touch positions. That is, the magnitude of mutual capacitance at edges or corners of the active area AA is less than that of the middle portion of the active area AA. Accordingly, after the touch, a change amount of mutual capacitance at edges or corners of the active area AA is also less than that of the middle portion of the active area AA
Referring to FIG. 2, the change mount of mutual capacitance according to the touch positions 1 to 4 will be described. If a touch is performed at the touch position 1, the change mount of mutual capacitance between the 1-3 touch electrode Tx13 and the 2-2 touch electrode Rx2 and the change mount of mutual capacitance between the 1-3 touch electrode Tx13 and the 2-3 touch electrode Rx3 are accumulated to calculate the total change amount of the mutual capacitance before and after the touch is performed.
If a touch is performed at the touch position 2, the change mount of mutual capacitance between the 1-3 touch electrode Tx13 and the 2-3 touch electrode Rx3 and the change mount of mutual capacitance between the 1-4 touch electrode Tx14 and the 2-3 touch electrode Rx3 are accumulated to calculate the total change amount of the mutual capacitance before and after the touch is performed.
If a touch is performed at the touch position 3, the change mount of mutual capacitance between the 1-4 touch electrode Tx14 and the 2-3 touch electrode Rx3 is calculated to obtain the total change amount of the mutual capacitance before and after the touch is performed.
If a touch is performed at the touch position 4, the change mount of mutual capacitance between the 1-4 touch electrode Tx14 and the 2-3 touch electrode Rx3 is calculated to obtain the total change amount of the mutual capacitance before and after the touch is performed. The change mount of mutual capacitance at the touch position 4 is less than that at the touch position 3 because the touch is performed on a corner of the 1-4 touch electrode Tx14 at the touch position 4 and the touch area at the touch position 4 is smaller than that at the touch position 3.
From the comparison of the change mounts of mutual capacitances at the touch positions 1 to 4, it is known that the change mounts of mutual capacitances at the touch positions 1 and 3 are similar to each other, the change mount of mutual capacitance at the touch position 3 is less than that at the touch position 1 or 2, and the change mount of mutual capacitance at the touch position 4 is less than that at the touch position 3.
As thus, the change amounts of the mutual capacitances at corner areas and edge areas are less than that at center area because the change amounts of mutual capacitances are different according to the touch positions. There are some problems in that touch accuracy and linearity at edge areas and corner areas of the active area AA are deteriorated.
Accordingly, it is required to prevent the touch accuracy and linearity from being deteriorated though touches are performed at edge areas and corner areas of the active area AA of the touch sensor integrated type display device.